Fuel pump



July 11, 1944. v; D. ROOSA 2,353,188

FUEL PUMP Filed April 26, 1941 2 Sheets-Sheet l INVENTOR Vkrnonfl 17mm ATTORNEY v. D. RoosA .Fuiy 11, 1944.

FUEL PUMP Filed April 26, 1941 2 Sheets-Shea?r 2 INVENTOR 72271011 2. E0050 a d ORNEY .1

a A i w Patented July 11, 1944 FUEL PUMP Vernon D. Roosa, Ardsley, N. Y., assignor of onel'ourth to Ernest J. Willson, Astoria, Long Island, N. Y.

Application April 26, 1941, Serial No. 390,492

Claims.

means for accurately controlling the amount of fuel fed to an engine.

Another object of the present invention is to combine in an efiicient manner a fuel charging or pick-up pump with a single piston pump for supply of successive charges in such a manner as to simplify the pump construction with an employment of common means to drive both, one

from the other.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein Fig. 1 is a. diagrammatic top plan view showing an arrangement of the present fuel pump with an internal combustion engine.

Fig. 2 is a longitudinal sectional view of the pump of Fig. 1, showing the relation of the pump parts for discharging fuel to an engine cylinder.

Fig. 3 is a sectional view along the line 3-3 of Fi 2, showing the relation of the pump parts for admitting fuel to the interior of the pump.

Fig. i is a horizontal sectional view along the line ll of Fig. 2.

Fig. 5 is a horizontal sectional view along the line Et-ti of Fig. 3.

Fig. 6 is a fragmentary sectional view, showing a fuel control valve in fully open position.

Fig. 7 is a fragmentary sectional view showing the fuel control valve of Fig. 6 in fully closed position.

Fig. 8 is a horizontal sectional view along the line 8-3 of Fig. 3.

Fig. 9 is an elevational view illustrating a means for automatically controlling the pump.

Fig. 10 is a fragmentary sectionalview illustrating a. modified form of the fuel receiving and injecting means; and

Fig. 11 is a fragmentary sectional view showing means for varying the time of injection of fuel to the cylinder of an engine.

Referring again to the drawings and more particularly to Figs. 1 to 3 thereof, there is shown an internal combustion engine I having the cylinders 2 thereof connected by fuel lines 4 with a fuel pump 5. The fuel pump 5 of the instant application may be driven by gears connected with the crankshaft or camshaft of an engine (not shown) and is particularly adaptable to internal combustion engines of the Diesel type which utilize theinjection of charges of fuel oil into injection nozzles, from which the fuel passes into the cylinders of an engine. The pump will be described chiefly with reference to such an engine.

The fuel pump 5 has a hollow casing member or body member I with a fuel pick-up or transfer pump til mounted therein. The easing l is attached by bolts or the like to a. gear box l2. A fuel inlet line 8 in the casing communicates with the transfer pump. A fuel outlet passage I i from the transfer pump ill has a fuel regulator valve therein, and is adapted to communicate periodically with the interior chamber H! of a hollow cylinder or rotor l-i secured to the trans fer pump ill.

The rotor it is rotated by means of a gear 44 up with appropriate passages or conduits -of'the casing. It will be noted (Figs. 2 and 3) that the sleeve member 9 terminates below the top of the casing member to leave an enlarged chamber above the sleeve.

A transfer pump l Bl is mounted within the enlarged chamber above the sleeve t. The transfer pump is preferably of the gear type, of which there are many on the market and is adapted to pick up fuel oil from a tank or other source of supply and deliver it under pressure to the injection part of the present pump. In the type illustrated herein, the transfer pump comprises a pair of intermeshing gear wheels l9 and 20 which cooperate with a substantially crescentshaped guide member 22 to transfer fuel oil from an inlet conduit 8 to a conduit or passage way II leading to the injectionpart of the pump.

This type of transfer pump is adapted to deliver fuel to the injection part of the pump under a pressure of approximately 50 pounds per square inch. The discharge side of the transfer pump may also connect, by a. passage 3, with a closed chamber or accumulator 6 which is adapted to minimize any pulsating effect that might possibly be caused by a transfer pump. The closed chamber or accumulator forms an air cushion which tends to even out pressure. pulsations and thus insures a steady fuel oil flow of substantially constant pressure in the fuel conduit II. Generally the accumulator B is not necessary as the transfer pump I9 itself delivers a substantially non-pulsating fiow of fuel oil.

The pressure under which the fuel is delivered to the injection part of the pump may be controlled by means of a pressure metering or regulating valve 23 (Fig. 4). The pressure regulating valve 33 is connectedwith the discharge side of the transfer pump I9 and may comprise a ball member 25 maintained on a seat 24 by means of a spring 26, the compression of which may be adjusted by means of a nut 28 screwed into the casing I. The ball member 25 may thus be set to unseat at any desired pressure. In the event the transfer pump builds up excess pressure at the discharge side thereof, the fuel oil pressure will be suflicient to unseat the ball member 25 from its seat 26. When this occurs, fuel oil may flow into and through the by-pass conduits 29 and 3i connected with the ball chamber 26. As shown in Fig. 4, these by-pass conduits connect with the inlet line 8 of the transfer pump and merely circulate the fuel oil through the pump until the pressure drops sufficiently to allow seating of the ball member 25. It will be clear that the by-pass lines could be connected with any-suitable storage tank or the like.

The passage of conduit H which communicates with the discharge side of the transfer pump I6 extends downwardly through the casing or body I of the pump to connect with an annular passage 21 that extends about the outer circumference of the sleeve member 9. The annular passage 2? is interrupted at suitable intervals about its circumference by inlet passages or ports 32 which extend completely through the sleeve 9 to the interior thereof. It will be clear that the annular passage 21 could be formed in the casing I itself, instead of in the sleeve member 9, and that the inlet ports would communicate with it in a similar manner. The passages 32 through the sleeve 9 are adapted to be opened and closed at intervals by means of the apertured rotor I4 fitted Within the sleeve 9 to admit and out off the passage offuel therethrough.

A metering pin or regulating valve 34 projects into the inlet conduit II through which fuel is admitted to the rotor part I4 of the pump. he metering pin 34 may be adjusted to vary the effective size of the inlet conduit I I which communicates with the injection part of the pum In the present embodiment this metering pin comprises a rod or pin that extends substantially at right angles into the conduit II and has its inner end recessed or cut away at one side thereof (Figs. 3, 6 and 'I). When the cut away part of the metering pin is in line with the inlet conduit II (Fig. 6), fuel may pass through the conduit and when the cut away part is turned completely away from the inlet conduit II, passage of fuel therethrough ma be entirely out off (Fig. '7). Between the extreme open and closed positions of Figs. 6 and 7, there are a large number of intermediate positions to which the metering pin 34 maybe adjusted. Preferably, the metering pin has an arm or crank 38 secured to its outer end to facilitate rotation of it and consequent adjustment of the fuel flow through the conduit II. In this way the quantity of fuel passing through the inlet conduit to the rotor I4 may be accurately and carefully controlled. Leakage of fuel oil along the metering pin 34 to the exterior of the pump ma be minimized by providing an annular recess 35 about the metering pin that communicates with an aperture 31 adjacent the lower part of the casing I. The annular passage 35 and aperture 3! collect the fuel that may leak along the shaft of the metering pin and directs it into the sump or gear chamber 36. It will be noted (Fig. 3) that the fuel passage II in the casing or body I of the pump is shown continuin downwardly past the metering pin 34 to merge with an inwardly extending passage 40 adjacent the lower part of the casing I and sleeve 9. The purpose of this passage 40 and its operation will be hereinafter described.

The rotor I4 referred to above comprises a cylindrical hollow member carefull machined and lapped so as to form a very close fit about its exterior surface with the carefully finished interior surface of the sleeve member 9. The rotor I4 is preferably secured at its upper end to the outer gear member 20 of the fuel transfer pump III, so that both the rotor and the transfer pump turn as a unit. Shrink fitting the rotor I4 and gear member 20 together has been found to provide a secure connection, but any othersuitable means of connecting them may be used. The rotor I4 is preferably rotated by a shaft 42 through the intermediation of gears 43 and 44.

The rotor I4 is provided with a longitudinally extending slot 46 therein which communicates with an aperture 49. During rotation of the rotor I4 the longitudinally extendin slots 46 and its connecting aperture 49 move into and out of registry With the inlet parts 32 and discharge ports 33 of the sleeve 9. When the slot and aperture 46-49 of the rotor are in line with an inlet port 32 of the sleeve, which connects with the vertical fuel inlet passage II, fuel oil charges may be admitted to the interior I3 of the rotor. The amount of fuel which flows through the inlet passage II into the interior of the rotor may be controlled by turning the metering valve or pin 34 to var the effective size of the fuel oil inlet passage II. As the rotor I4 turns within the sleeve member 9 the slot and aperture 4649 thereof will move out of registry with an inlet port 32 and into registry with a discharge port 33 (Fig. 2). In this latter position the fuel charge admitted to the interior I3 of the rotor may be discharged by the piston I'I through the aperture and slot 46--49 to a discharge line 50 which leads to an injection nozzle of one of the cylinders. The inlet ports 32 are spaced at intervals around the circumference of the sleeve 9 in substantially a single plane and as the rotor turns the slot and the aperture 46-49 thereof communicates with them successively. The exit ports 33 which lead to the inlet lines for the cylinders are likewise spaced at intervals about the circumference of the sleeve 9 in substantially a single plane but they are at a different level than the inlet ports. Also, the discharge ports are not in vertical alignment with the inlet ports but are spaced circumferentially with respect to them; thus the aperture and slot 46-49 of the rotor I4 is at no time charge conduit till.

in communication with more than one entrance passage 22 or onedischarge passage 33. In the present instance the preferred emhodiment of the fuel pump is shown and described with reference to its adaption to a six-cylinder engine, but it will be clear that any desired number of cylinders ma be utilized. The number of cylinders of the engine will determine the number of inlet ports 32 and discharge ports 33, one inlet port and one discharge port being preferably utilized for each cylinder of the engine. If desired, the rotor it may be provided with a plurality of inlet ports to communicate at intervals with a single inlet port in the sleeve a 'By utilizing a longitudinally extending slot it in the rotor I8 two advantages are obtained. First, a plurality of separate inlet and discharge pofts need not be drilled into the rotor; instead, the single long slot may be easily cut or milled into the side of the rotor. Secondly, the long slot is operative to maintain a him of oil over a substantially large portion of the contact area between the sleeve 9 and rotor it. film of oil extends the entire length ofthe slot t and turningof the rotor distributes the film over the circumferential area of the sleeve. An

W of the rotor and serves a purpose to be later described.

The piston it is fitted within the rotor m and reciprocates therein to periodically cause the discharge of fuel oil. from the rotor chamber iii into conduits lit leading to injection nozzles of an englue. When the slot and aperture case are in communication with an inlet port 32, and the metering pin M is in open position, fuel will be admitted to the rotor chamber is. As the rotor tunic, the entrance port 32 is closed and the slot and aperture iii-At move into registry with a discharge port When the slot and discharge port it are in registry, upward movement of the piston it forces fuel out through the dis- In the preferred emhodie nient upward movement of the piston is effected by means of a cam 53 fixed to, ground on,- or otherwise formed or carried by the shaft t2.

Preferably the lower end 55 of the piston has a square shoulder which fits into a groove 56 of the cam 53 to prevent rotary movement of the piston ll under the influence of the rotary motion of the rotor it. This minimizes any tendency of the piston. to stick to the rotor id and remain in its upper position.

Downward movement of the piston it from an elevated position in the rotor M is achieved by fuel which enters the chamber is of the rotor under pressure which is built up by the trans fer pump secured to the upper end of the rotor. The distance that the piston will be forced downwardly in the rotor depends upon the size of the opening through the metering pin 3 and the speed of the engine. When the opening through the metering pin at is large, a considerable quantity of fuel may flow into the chamber it in a given time and the piston i! will be forced down relatively far. When the opening through the metering pin 38 is small, a lesser amount of fuel can enter the chamber l3 in a given time,

That is, a

- cylinder.

of the engine since the rotor I4 is driven by gears 43 and secured to the engine-driven shaft 42. The faster the speed of the motor the less time the slot and aperture remain in registry and the less fuel is injected for each charge. This has an automatic governing effect tending to prevent excessive speeds. Any desired ratios between the gears 58, 43 and 44 of the pump and the'cooperating engine gears (not shown) may be utilized to achieve the desired timing for the injection of fuel into the cylinders of the engine. In the present embodiment the gears 63 and i l have a ratio of oneto one since the pump illus trated is adaptable for use with a six-cylinder engine having appropriate gears for driving the shaft 42 at one-half of the crankshaft speed.

In operation, the gear driven rotor 44 turns the pump it, which is operative to pick up fuel from a source of supply and deliver it under pressure to the inlet conduit II. The amount of fuel passing through. the inlet conduit ii is controlled by adjusting the metering pin or valve 36 for the desired conditions of load and speed of the engine. Fuel passes from the conduit it through the slot and aperture 46-49 of the rotor it and into the rotorchamber it. In the preferred embodiment fuel is admitted to the rotor chamber it each time that the slot and aperture 46-49 communicate with an inlet port 32 of the sleeve 9. Fuel charges are periodically elected by the piston it from. the rotor chamber iii, which is connected through discharge ports 33 with conduits ht leading to the injection nozzles of an engine. The piston i7 is reciprocated by a cam in timed relation with re 'spect to the rotation of the rotor It. When the rotor port 48-49 is in communication with the inlet ports 32 and conduit ii, the piston is free the fuel oil into the fuel discharge conduit 5t,

which leads to the injection nozzle of an engine cylinder. into the engine cylinders. A desirable feature oi an injection nozzle is its ability to out off sharply the flow of fuel into a cylinder. One way of facilitating this is to quickly reduce the pressure in the fuel line leading to a particular injection nozzle, so that back pressure behind a valve in the nozzle is decreased and the valve does not have to seat in opposition to a high fuel pressure. The pump described herein embodies such a back pressure reducing feature. That is, the pump piston I1 is first moved upwardly by cam 53 and forces fuel through the fuel lines and injection nozzles; as the cam continues to rotate, it starts to lower the piston ll. Lowering the piston ii in the pump cylinder reduces the pressure in the fuel inlet line. This reduces the pressure acting against an injection nozzle valve and allows thisv valve to seat more rapidly than would be true if it had to seat itself in opposition to the full force of the injection pressure caused by the piston H. The injection nozzle valve thus cuts 017 more sharply the passage of fuel into an engine The reduction in back pressure in a fuel line 50 is of only momentary duration, for further rotation of the pump cylinder cuts off the exit port which communicates with a conduit 50.

The piston stroke is variable due to the fact that the piston l'l tends to normally remain in From the injection nozzles fuel passes an upward position within the rotor chamber 13 until acted upon by fuel which enters chamber I3 under pressure. The distance that the piston i1 is forced downwardly by the incoming fuel depends upon the amount of fuel that enters the chamber i3 in a given time; this is controlled firstly by the size of opening through the metering valve 34 and secondly by the speed at which the slot and aperture 46-48 of the rotor pass the fuel inlet ports 32.

In some instances an engine must be primed in order to start it. For example, the conduits leading to the injection nozzles of an engine may contain no fuel. The passage 40 in the pump casing 1 and the annular recess 52 adjacent the lower part of the rotor 14 (Fig. 3) may be used to facilitate priming. To perform this function holding flange 39 may be loosened to permit partial-withdrawal of th metering .pin 34 from the fuel inlet passage ll. Oil may then pass freely through the fuel inlet conduit ll, into the horizontal fuel passage 40, around the annular rotor recess 52, through the slot and aperture 46-46 of the rotor, and into the rotor chamber i3. From the rotor chamber i3, the fuel may fiow into and fill a conduit 50 leading to an engine injection nozzle. The fuel lines or conduits of each engine cylinder may be filled with oil in a similar manner by turning the engine over.

In Fig. there is illustrated a modified form of fuel pump wherein a piston Ha is operated by means of a spring 59 rather than by a cam as described in connection with Figs. 2 and 3. The piston l1a has a shoulder 6| that fits into a recess 62 at the lower part of the rotor to limit excessive movement of the piston within the rotor. Fuel entering the chamber 1341 through the inlet passages the ports Ila and 32a forces the spring controlled piston l1a downwardly. Rotation of the rotor brings an exit slot and aperture thereof into communication with an exit port and the spring 59 then forces the piston upwardly to discharge fuel into a conduit leading to an engine cylinder. 'An aperture 63 is preferably drilled through the gear 440 adjacent the lower part of the piston so that the interior of the piston communicates with the interior of the gear chamber l2; the interior of the piston is thus vented at all times to minimize the possibility of the piston locking to the gear and failing to properly eject fuel from the chamber I311.

A preferred means for obtaining automatic operation of the pump will now be described. The metering pin or valve 34 is illustrated in Fig. 3 as connected with a lever arm 38. The

lever arm may, in such event, be connected by suitable linkage with a throttle lever placed at some relatively remote location so that the speed of the engine may be varied therefrom. The pump is also adapted to be controlled automatically by means of a governor mechanism connected with the drive shaft for the pump. One end 45 of the pump drive shaft 42 is provided with an outwardly projecting portion 61, preferably of smaller diameter than other parts of the shaft 42 (Fig. 2). An internally threaded nut member 65, having outwardly projecting arms 68 secured thereto is fitted over the shaft projection 61 and screwed into engagement with cooperating threads on the shaft 42. Adjacent the outer ends of the arms 68 are pivot-ally secured weight members 10. A sleeve member 1| having flanges 69 and 12 thereon is fitted over the projection 61 of the shaft 42 so that it may freely rotate and slide with respect to the projection 61; the projection 61 thus operates as a guide for the collar member 1|. Rotation of the drive shaft 42 is effective to rotate the nut member 65 threaded thereto, and to also turn the projections 68 of the nut member which carry the pivoted governor weights 16. These pivoted weights 16 tend to fly outwardly due to centrifugal force as the shaft 42 is rotated and inwardly curved projections 66 on the weights press against the flange 66 of the sleeve member 1|, tending to force it axially along the rod-like projection 61. As the sleeve member 1| moves outwardly along the projection 61, a flange 12 on the sleeve member 1| presses against a thrust bearing 15 and the latter in turn presses against the end of an arm 13 which is fixedly secured to a shaft 16 (Fig. 2). The shaft 16 acts as a pivot for links 11 and 19 (Fig. 9) by means of which the metering pin lever 38 may be rotated. A tension spring 80, secured at one end 82 to the governor housing and at the other end to the link 11, serves to pull the end of the arm 13 firmly against the thrust bearing 15 within the governor housing.

At normal speeds the tension of the spring 88 is suflicient to maintain the arm 13 in the position shown in Fig. 2. If, however, the engine should tend to speed up excessively for any reason the pivoted weights 10 of the governor tend to fly outwardly out their pivot points due to centrifugal force, thus causing the flange 1.2 and thrust bearing 15 to move the arm 13 outwardly in opposition to the force of the tension spring 86. The exterior link members 11 and 18 (Fig. 9) move the metering pin arm 38 and thus vary the size of the opening through the metering valve 34 and the quantity of fuel passing into the injection part of the pump. When the amount of fuel decreases the engine will slow down.

In Fig. 11 there is illustrated a mechanism which may be used to vary the time of injection of fuel into the engine cylinders and also to eliminate side thrust of a cam against a piston l1b. A piston supporting arm 82 has adjacent one end thereof a substantially cup-shaped portion 83 into which is fitted the lower end of the piston ND. The piston l1b preferably has flattened side portions adjacent its lower end which fit into a recess adapted to prevent rotation thereof with respect to the rotor I 4b, as described in connection with the preferred embodiment. Also, makin the lower end of the piston rounded, with a slightly smaller radius of curvature than the interior of the cup-shaped portion facilitates movement of the piston supporting arms hereinafter described. The opposite end 85 of the piston supporting arm 82 is eccentrically mounted on shaft 86. Rotation of the drive shaft 42b and cam 53b moves the cam surface into and out of contact with the under side of the cup-shaped portion 83; the cam thus does not act directly against the piston [11). Any side thrust against the piston caused by rotation of the cam is directed against the under side of the cup-shaped portion and is not communicated to the lower end of the piston l1b. The piston no is thus subjected to only the vertical effect of the cam movement. This modification is particularly useful in instances wherethe pump is designed for use with engines which require injection of fuel charges at relatively high pressures. Another feature of the arm mounting arrangement of Fig. 11 is to change the time of the injection of fuel into the engine cylinders. The shaft 86 may be moved to shift the horizontal position of the piston supporting arm 82 to the right or to the left (Fig. 11). Shifting the arm in this manner varies the time of contact between the under surface of the cup-shaped portion 83 and the surface of the cam 53b. For example, if the arm 82 is moved to the right from the position shown in Fig. 11, earn lift 38 will contact the under side of the cup-shaped portion sooner than when the arm is in the position illustrated in Fig. 11. Thus, the piston l'lb will move upwardly within the rotor earlier than when the lever is in the position illustrated in Fig. 11. This is effective to vary the time of injection of fuel into the engine cylinders.

It will be seen that the present invention provides .a new and improved pump for supplying charges of fuel oil to an internal combustion engine. The pump is relatively simple in construction and operation, has few parts, and may be readily assembled or disassembled for construction or repair. The pump utilizes a minimum number of moving parts. No great amount of knowledge or skill is required on the part of the average mechanic in order to thoroughly understand the construction and operation of the pump. Fuel oil charges may be accurately measured and controlled by a simple valve construction which requires very little effort to operate; thus a minimum size governor may be utilized and close speed regulation still obtained. Fuel oil is both picked up from a source of supply and injected into an engine by a single compact unit. By reason of its simplicity, the pump may be inexpensively manufactured and sold.

As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. A fuel pump comprising, in combination, a casing having fuel inlet and outlet passages, a hollow cylinder rotatablymounted in said casing having fuel inlet and outlet passages adapted to connect at intervals during the rotation of said cylinder with the respective inlet and outlet pas sages of said casing to facilitate admission and discharge of fuel to and from the interior of said cylinder, means for continuously rotating said cylinder when the pump is in operation, adjustable valve means operatively connected with one of said fuel inlet passages for controlling the effective size thereof and the quantity of fuel entering the interior of said rotatable cylinder, a piston in said rotatable cylinder adapted to move downwardly a distance corresponding to the amount of the entering fuel charge, and means for moving said piston so as to discharge fuel through an outlet passage of said cylinder.

2. A fuel pump comprising, in combination, a hollow casing having fuel inlet and outlet passages, a liner in said hollow casing having fuel inlet and outlet ports connecting with the fuel inlet and outlet passages of said casing, a hollow cylinder rotatably mounted in said liner having fuel inlet and outlet passages adapted to connect at intervals during the rotation of said cylinder with the respective inlet and outlet passages of said casing to facilitate admission and discharge of fuel to and from the interior of said cylinder, means for continuously rotating said cylinder, adjustable valve means operatively connected with one of said fuel inlet passages for controlling the effective size thereof and the quantity of fuel entering the interior of said cylinder, a reciprocable piston in said pump cylinder adapted to move downwardly a distance corresponding to the amount of the entering fuel charge, and means for reciprocating said piston to thereby periodically discharge fuel through an outlet passage of said cylinder.

3. A fuel pump comprising, in combination, a casin having fuel inlet and outlet passages, a hollow cylinder rotatably mounted in said casing having fuel inlet and outlet passages adapted to connect at intervals with the respective inlet and outlet passages of said casing to facilitate admission and discharge of fuel to and from the interior of said cylinder, means for continuously rotating said cylinder, means operatively connected with one of said fuel inlet passages for controlling the quantity of fuel passing through said passage and entering the interior of said pump cylinder, a piston freely mounted in said cylinder adapted to be moved in one direction by the entering fuel charge, and means for moving said piston in an opposite direction so as to discharge fuel through an outlet passage of said cylinder.

4. A fuel pump comprising, in combination, a casing having fuel inlet and outlet passages, a hollow cylinder rotatably mounted in said casing having fuel inlet and outlet passages adapted to connect at intervals with the respective inlet and outlet passages of. said casing to facilitate admission and discharge of fuel to and from the interior of said cylinder, means for continuously rotating said cylinder, a piston in said cylinder, means operatively connected with one of said fuel inlet passages leading to the pump cylinder for controlling the quantity of fuel entering the interior of said pump cylinder, the quantity of fuel entering said cylinder determining the distance said piston moves downwardly, and means for moving said piston so as to discharge fuel through an outlet passage of said cylinder.

5. A fuel pump comprising, in combination, a casing having a chamber adapted to receive a gear type pump and also having inlet and outlet passages leading to and from said chamber, a gear type pump mounted in said chamber, a rotatable hollow cylinder mounted in said casing adjacent said gear type pump and operatively connected with said gear type pump, said rotatable cylinder having an inlet passage adapted to connect at intervals with the outlet passage leading from said pump chamber to admit fuel to the interior of said rotatable cylinder and having an outlet passage adapted to connect at intervals with conduits for conducting fuel to an engine, means for rotating said cylinder, and a piston Within the rotatable hollow cylinder adapted to periodically expel fuel from said cylinder to the fuel conduit of an engine.

6. A fuel pump comprising, in combination, a casing having a chamber adapted to receive a gear type pump and also having inlet and outlet passages leading to and from said chamber, a gear type pump mounted in said chamber, means for by-passing fuel in the event of excessive pressure in said fuel passage, a rotatable hollow cylinder in said casing adjacent said gear type pump and operatively connected with said gear type pump, said rotatable cylinder having an inlet passage adapted to connect at intervals with the outlet passage leading from said pump chamber to admit fuel to the interior of said rotatable cylinderand having an outlet passage adapted to connect at intervals with conduits for conducting fuel to an engine, means for rotating said cylinder, and a piston within the rotatable hollow cylinder, adapted to periodically expel fuel from said cylinder to the fuel conduit of an engine.

7. A fuel pump of the class described comprising, in combination, a casing having a chamber adapted to receive a fuel pick-up pump and having fuel inlet and outlet passages leading to and from said chamber, a fuel pick-up pump mounted in said chamber adapted to receive fuel from a source of supply and deliver it to an outlet passage of said chamber, a rotatable hollow cylinder mounted in said casing and operatively connected with said fuel pick-up pump for driving it, said hollow cylinder having a fuel entrance passage adapted to connect at intervals with an outlet passage of said chamber to admit fuel to the cylinder andalso having a fuel exit port, means for rotating said cylinder, and a piston in said cylinder adapted to periodically ejectsaid fuel from the cylinder thru an exit port.

8. A fuel pump of the class described, comprising, in combination, a casing having fuel inlet and outlet passages, a rotary type fuel pickup pump carried by said casing adapted to receive fuel from a source of supply and deliver it under pressure to an outlet passage of said casing, a rotatable hollow cylinder mounted in said casing and directly connected to said fuel pickup pump for driving the latter, said hollow cylinder having a fuel entrance passage adapted to connect at intervals with an outlet passage of said casing to admit fuel to the interior of the cylinder and also having a fuel exit port, means for rotating said cylinder, and a piston in said cylinder adapted to periodically eject said fuel from the cylinder thru an exit port.

9. A fuel pump of the class described, comprising, in combination, a casing having fuel inlet and outlet passages, a rotatable hollow cylinder mounted in said casing having a fuel passage adapted to connect at intervals with the respective inlet and outlet passages of said casing to facilitate entry and discharge of fuel to and from the interior of said cylinder, means for rotating said cylinder, a piston in said cylinder, a measuring valve located in the fuel inlet passage leading to the interior of said pump cylinder for measuring the amount of fuel going to said cylinder without requiring adjustment of the piston movement, and means for moving said piston so as to discharge measured amounts of fuel from the cylinder through an outlet passage of the cylinder.

10. A fuel pump of the class described, comprising, in combination, a casing having fuel inlet and outlet passages, a rotatable hollow cylinder mounted in said casing having a fuel passage adapted to connect at intervals with the respective inlet and outlet passages of said casing to facilitate entry and discharge of fuel to and from the interior of said cylinder, means for rotating said cylinder, a piston in said cylinder, valve means comprising a rotatably adjustable pin having a recess at one side thereof extending into the fuel inlet passage leading to the interior of said pump cylinder for controlling the amount of fuel going to said cylinder without requiring adjustment of the piston movement, and means for moving said piston so as to discharge controlled amounts of fuel from the .cylinder through an outlet passage of the cylinder.

11. A fuel pump of the class described, comprising, in combination, a hollow casing having main fuel inlet and outlet passages and having a normally closed auxiliary fuel inlet passage, a rotatable hollow cylinder mounted within said casing having a fuel passage adapted to connect at intervals with the inlet and outlet passages of said casing to facilitate entry and discharge of fuel to and from the interior of said cylinder, means for rotating said cylinder, valve means located in the main inlet passage of said hollow casing for controlling the amount of fuel going to said cylinder and adapted to be moved to permit the free passage of fuel through said auxiliary inlet passage into said cylinder, and means for normally ejecting fuel from said hollow cylinder into conduits leading to the cylinders of an engine.

l2. A fuel pump of the class described, comprising, in combination, a casing having fuel inlet and outlet passages, a rotatable hollow cyl-w inder mounted in said casing having fuel inlet and outlet passages adapted to connect at intervals with the respective inlet and outlet passages-of said casing to facilitate entry and discharge of fuel to and from the interior of said cylinder, means adapted to continuously rotate said cylinder when the pump is in operation, adjustable valve means located in the fuel inlet passage leading to the interior of said pump cylinder for measuring the amount of fuel going to said cylinder, a piston in said cylinder adapted to be moved in one direction in response to the fuel which enters said cylinder, and cam means for moving said piston in an opposite direction so as to discharge fuel from the cylinder through an outlet passage of the cylinder.

13. A fuel pump of the class described, comprising, in combination, a casing having fuel inlet and outlet passages, a rotatable hollow cylinder mounted in said casing having fuel inlet and outlet passages adapted to connect at intervals with the respective inlet and outlet passages of said casing to facilitate entry and discharge of fuel to and from the interior of said cylinder, means adapted to rotate said cylinder, valve means located in the fuel passage leading to the interior of said cylinder for controlling the amount of fuel going to said cylinder, a piston in said cylinder, and resilient means connected with said piston for moving it so as to discharge fuel from the cylinder through an outlet passage of the cylinder.

14. A fuel pump of the class described, comprising, in combination, a casing having fuel inlet and outlet passages, a rotatable hollow cylinder mounted in said casing having fuel inlet and outlet passages adapted to connect at intervals with the respective inlet and outlet passages of said casing to facilitate entry and discharge of fuel to and from the interior of said cylinder, means adapted to rotate said cylinder, valve means located in the fuel passage leading to the interior of said cylinder for controlling the amount of fuel going to said cylinder, a piston in said cylinder having means for venting the interior thereof, and resilient means connected with said piston for moving it so as to discharge fuel from the cylinder through an outlet passage of the cylinder.

15. A fuel pump of the class described, comprising, in combination, a casing, a hollow cylinder rotatably mounted within said casing, said casing and cylinder having passages therein for conducting fuel to and from the interior of said hollow cylinder, means adapted continuously rotate said cylinder when the pump is in operation, means in one of said fuel passage for controlling the amounts of fuel which enter said cylinder, a piston in said cylinder adapted to move under the influence of the fuel which enters said cylinder, and resilient means for moving said piston to thereby discharge fuel from the cylinder to a conduit leading to an engine; 7

16. A fuel pump of the class described, comprising, in combination, a casing, a hollow cylinder rotatably mounted within said casing, said casing and cylinder having passages therein for conducting fuel to and from the interior of said hollow cylinder, means adapted to rotate said cylinder, valve means in one of said fuel passages adapted to be used in controlling the sizes of the fuel charges which enter said cylinder, a piston in said cylinder adapted to move downwardly under the influence of the fuel which enters said cylinder 2. distance corresponding to the amount of the entering fuel charge, and means for moving said piston upwardly to discharge iuel from the cylinder to a conduit leading to an engine.

1'7. A fuel pump comprising, in combination, a casing having fuel inlet and outlet passages, a hollow cylinder rotatably mounted in said casing having fuel inlet and outlet passages adapted to connect at intervals with the respective inlet and outlet passages of said casing to facilitate admission and discharge of fuel to and from the interior of said cylinder, means for rotating said cylinder, means operatively connected with one of said fuel inlet passages for controlling the quantity of fuel entering the interior of said cylinder, a piston in said cylinder, means for moving said piston so as to discharge fuel through an outlet passage of said cylinder, and an adjustable arm having a portion located intermediate said piston and said piston moving means adapted to be moved to vary the time with respect to the piston stroke of an engine, at

a which the piston is effective to discharge fuel through said outlet passage.

18. A fuel pump comprising, in combination, a casing having fuel inlet and outlet passages, a hollow cylinder rotatably mounted in said casing having fuel inlet and outlet passages adapted to connect at intervals with the respective inlet and outlet passages of said casing to facilitate admission and discharge of fuel to and from. the interior of said cylinder, means for rotating said cylinder, means operatively connected with one of said fuel inlet passages for controlling the quantity of fuel entering the interior of said cylinder, a piston in said cylinder,

cam means for moving said piston so as to discharge fuel' through an outlet passage of said cylinder, and an adjustable arm having a por-- tion located intermediate said cam and piston and adapted to be utilized to vary the time at which the piston is effective to discharge fuel through said outlet passage.

19. A fuel pump comprising, in combination, a casing having a fuel pick-up pump chamber and a fuel inlet passage leading from the chamber and outlet passages, a movable fuel pick-up element mounted in the chamber adapted to deliver to the fuel inlet passage fuel under pressure, a hollow cylinder rotatably mounted in said casing having fuel inlet and outlet passages adapted to connect at intervals with the respective inlet and outlet passages of said casing to facilitate admission and discharge of fuel to and from the interior of said cylinder, means for rotating said cylinder, said movable fuel pickup pump element being operatively connected to said cylinder to be driven thereby, means operatively connected with said fuel inlet passage for controlling the quantity of fuel passing through said passage and entering the interior of said pump cylinder, a piston freely mounted in said cylinder adapted to be moved in one direction by the entering fuel charge, and means for moving said piston in an opposite direction so as to discharge fuel through an outlet passage of said cylinder.

20. A fuel pump comprising, in combination, casing means having a fuel pick-up pump chamber, a fuel supply inlet passage communicating therewith, a circular bore, at least one inlet passage interconnecting the chamber and bore, and outlet passages terminating at the bore; a hollow cylinder rotatably mounted in the bore providing a piston pump bore and having at least one passage extending therethrough for periodic discharge of fuel from the pump bore to outlet passages; means for rotating said cylinder; said cylinder during rotation being adapted periodically to valve the interconnecting inlet passage for successive admission of fuel charges to the pump bore; movable pump means in the chamber to draw fuel thereinto and deliver it under pressure into the interconnecting passage; means interposed between said pump means and said cylinder for operation of the former by the latter; a piston in the pump bore; and means periodically to move said piston inwardly on the ejection stroke to eject successive charges of fuel from the pump bore to the outlet passages.

, VERNON D. ROO'SA. 

